1. Field of the Invention
The present invention relates generally to the detection of air and water and, at least in certain embodiments, foam in a medium external to an optical sensor. Particularly, the sensor is configured for use in a washing machine, a dishwasher, or another environment in which it is desired to detect a presence of water, air, or foam in an environment.
2. Description of the Prior Art
Existing sensors for detecting a presence of water, air, or foam may suffer from the drawback that they may be expensive to produce, or may have a complicated internal structure. Some known sensors are configured such that a light source and a light sensor are positioned on a rear side of a lens to sense a composition of a medium external to the lens. Such sensors suffer from the drawbacks that the pieces of the sensors are expensive to produce, and the individual components of the sensors are difficult to assemble.
Additionally, sensors for detecting a present of water, air, or foam may have the disadvantage of being susceptible to becoming encrusted with deposits on a sensing surface, which may cause the sensor to provide inaccurate readings.
Therefore, what is needed is a water-air-foam detector that can provide accurate results and be manufactured economically.